ANESTHETIC-POSTOPERATIVE MORPHINE REGIMENS FOR CESAREAN-SECTION AND POSTOPERATIVE OXYGEN-SATURATION MONITORED BY A TELEMETRIC PULSE OXIMETRY NETWORK FOR 24 CONTINUOUS HOURS

Study Objective: To document the effects of compromised respiratory function on oxygen saturation (SpO(2)) after cesarean section via the telemetric pulse oximetry network (TPON) for 24 continuous hours. Design: Prospective study. Setting: Postpartum ward of a university hospital. Patients: ASA physical status I or II parturients undergoing cesarean section. Interventions: Healthy parturients were assigned to 1 of 3 anesthetic-postoperative morphine regimens as follows: general anesthesia-parenteral morphine as needed (GA/PM; n = 11); epidural anesthesia-parenteral morphine as needed (EA/PM; n = 15); epidural anesthesia-epidural morphine 4 to 5 mg (EA/EM; n = 10). Measurements and Main Results: For 24 continuous hours after cesarean section, SpO(2) heart rate, and plethysmogram every 10 seconds were recorded by the TPON computer In addition, pain, somnolence, respiratory rate (RR), and side effects were recorded every 30 minutes to 2 hours. SpO(2) less than 94% and less than 92% occurred least with GA/PM. The highest mean cumulative time of SpO(2) between 95% and 90% occurred with EA/EM. The longest episode of SpO(2) less than 92% and the lowest SpO(2) for more than 1 minute also occurred with EA/EM. With all 3 regimens, SpO(2) decreased to less than 80% for 20 to 30 seconds at a time, but the lowest SpO(2) (less than 85%) for more than 1 minute occurred with EA/EM in 1 patient and was associated with somnolence that required treatment. With all 3 regimens, average RR was within normal limits, but mean RR was significantly lower with EA/EM than with GA/PM or EA/PM from the 8th to the 14th postoperative hours. Somnolence did not differ significantly among the 3 regimens. Pain score was significantly lower with EA/EM than with GA/PM or EA/PM for the first 20 hours. Conclusions: All 3 regimens risked low SpO(2) with the EA/EM regimen having the highest risk but the best analgesia. Neither general nor epidural anesthesia combined with postoperative parenteral morphine influenced SpO(2) postoperatively. In this study, the TPON provided a feasible method of detecting hypoxemia early on in the general ward setting.